WATCH: U.S. marines strip down for war games in the snow

PYEONGCHANG, South Korea (CBS News) — About 400 South Korean and U.S. marines stripped off their shirts and flung snow at each other during a joint military drill aimed at increasing cooperation and endurance.

The training, which took place on February 7, included armed marines skiing down a snow-covered slope while aiming guns at hypothetical enemies and simulating war in the snow.

“This is the first joint winter dill between the United States and South Korea. The training envisions the entire Korean peninsula as the operating ground and focusing on increasing joint operation skills,” said Lieutenant Colonel Lee Keun-soo.

“As soon as we get the order, we will be the first to move toward the enemy to destroy them wherever we are,” he added.

The drill was held in the ski resort town of Pyeongchang, about 113 miles east of Seoul, which is also the venue for the 2018 Winter Olympics.

The United States has about 30,000 troops in South Korea to support the country’s 650,000-strong armed forces. Neighboring North Korea has some 1.2 million troops, mostly stationed along the border.

This year’s exercise was held amid high tensions in the region due to a possible third North Korean nuclear test.

North and South Korea are still technically at war because their 1950-53 conflict ended in a truce, not a treaty.